One of the greatest inventions of the 20th century, if not the greatest, was the transistor. It revolutionized the electronics industry and changed the way people around the world lived, learned, worked, and played. Its invention marked the beginning of solid state electronics which quickly reduced the size and power requirements of existing electronic tube […]
Chemistry • Condensed matter • Materials • Nanotechnology • Quantum physics
Usually, optical activity is understood as the ability some substances have to change the handedness of polarized light when it goes through them. Molecules that show optical activity have no plane of symmetry. The commonest case of this is in organic compounds in which a carbon atom is linked to four different groups. An atom […]
A quantum dot (QD) is a nanometric crystalline structure of semiconductor materials. In a QD electrons are confined in a region of space, thus creating a well defined structure of energy levels that depends very much on the size and shape of the quantum dot. This structure resembles that of atoms, that is why sometimes […]
A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. As the catalyst itself takes part in the reaction it may undergo a physical change. Metal complexes are typically regarded as catalysts that convert organic substrates into more valuable compounds; however, to date, catalytic transformations […]
Spallation is a type of nuclear reaction in which the interacting nuclei disintegrate into a large number of protons, neutrons and other light particles, rather than exchanging nucleons between them. It is thought that most of the nuclei of light elements, such as boron, are made in this way. Spallation reactions of this type are […]
There are chemical compounds, called isomers, that have the same molecular formulae but different molecular structures or different arrangements of atoms in space. In constitutional isomerism the molecules have different molecular structures: i.e., they may be different types of compound, or they may simply differ in the position of the functional group in the molecule […]
Condensed matter • Materials • Physics • Theoretical physics
The interactions between moving charges and magnetic fields can be quite complicated; more if we consider the quantum effects. One example is the collection of Hall effects. Imagine that we have a conductor or a semiconductor through which a current is flowing. Then we apply a strong transverse magnetic field. As a result, we can […]
Proteins can perform a huge number of biological functions with amazing efficiency. In order to achieve these different functions, proteins rely on the precise 3D arrangement of functional groups which are referred to as the protein fold. Some of these functions include acting as a catalyst in biochemical reactions; in these cases proteins are called […]
Achieving room temperature superconductivity is among the most pursued but elusive goals of scientists. I n December 2014 researchers claimed to have observed superconductivity as high as 200 K in hydrogen sulfide at high pressure, breaking all the records thus far. This meant that cuprates could be knocked from their position as the highest temperature […]
Condensed matter • Materials • Nanotechnology • Quantum physics • Theoretical physics
Plasmonic nanostructures confine light to dimensions far smaller than the free-space wavelength, as they mix optical fields with electronic excitations. It was not until the 1990s, with the appearance of accurate and reliable nanofabrication techniques, that plasmonics blossomed. It was found then that local fields around nanostructures could be directly measured by near-field scanning optical […]